Inhibition of gastric acid secretion by a glycoprotein isolated from human urine (human urinary gastric inhibitor)

Inhibitory effect of neurotensin on pentagastrin-stimulated gastric acid secretion in pylorus-ligated rats

Neurotensin is a known inhibitor of gastrin-stimulated acid secretion in dogs and humans. In order to study the dose-related effect of neurotensin, we prepared pentobarbital-anesthetized rats by pyloric ligation and collected gastric secretions one hour after injection of saline (Basal), pentagastrin, 6 micrograms/Kg subcutaneously (PG Alone), or pentagastrin plus neurotensin by tail vein injection (PG + NT). Acid output was calculated from the volume and pH of the samples, which correlated well with the output determined by titration with 0.02 N NaOH (r = 0.92). Basal output was 36 +/- 4 muEq/hr; stimulated output (PG Alone) was 64 +/- 5 muEq/hr, and output after PG + NT, 250 pmol/Kg, was 33 +/- 3 muEq/hr (p less than 0.001). The effect of neurotensin was dose-related over a range from 125 to 500 pmol/Kg. This technique may be useful in the biological evaluation of neurotensin-related peptides.

Comparison of human urine gastric inhibitor (HUGI) and bacterial endotoxin as inhibitors of acid secretion

In conscious cats with gastric fistulas, 10 micrograms . kg-1 of human urinary gastric inhibitor (HUGI) given as an intravenous bolus injection increased mean rectal temperature 1.4 degree C and inhibited mean gastrin-stimulated acid secretion by 64%. The sample of HUGI contained an amount of beta-hydroxymyristic acid corresponding to a 5% contamination of the HUGI with bacterial endotoxin. Injection of bacterial endotoxin in an amount corresponding to the beta-hydroxymyritic acid content of HUGI mimicked, both in magnitude and time course, the increase in body temperature and the inhibition of acid secretion produced by HUGI. We conclude that inhibition of acid secretion by HUGI may be due to the presence of an endotoxin-like contaminant.